Language Servers in Emacs

I use eglot as my language client since it is available out of the box and integrates nicely with core packages like xref

emacs/init.el

(use-package eglot
  :bind (("<f2>" . eglot-rename))
  :custom
  (eglot-autoshutdown t)
  (eglot-extend-to-xref t)
  :config
  (advice-add 'eglot--workspace-configuration-plist :around #'alc-eglot-fix-workspace-configuration-scope)

  (add-to-list 'display-buffer-alist
               '("\\*EGLOT workspace configuration\\*"
                 (display-buffer-below-selected)
                 (dedicated . t))))

Workspace Configuration

Convincing eglot to apply the correct workspace/configuration settings for the current server and project is the single most frustrating part of using it…

One issue is making sure eglot evaluates settings at the right scope

emacs/init.el

(require 's)

(defun alc-eglot-fix-workspace-configuration-scope (orig-fun server &optional path)
  "Fix the scopeUri of a workspace/configuration request.

When eglot handles a workspace/configuration request with an
associated scopeUri it uses the `file-name-directory' function to
determine the directory from which to resolve the configuration
values.

This causes an issue for servers like esbonio and pyright which
set the scopeUri to a directory. For `file-name-directory' to
treat the path as a directory it must include a trailing slash, a
convention which these servers do not follow.

Therefore `file-name-directory' treats the path as a file and
removes the final component, causing eglot to resolve the
configuration relative to the wrong directory.

This function fixes the issue by advising the
`eglot--workspace-configuration-plist' function, ensuring that
paths referencing directories include the trailing slash."
  (if (and path
           (file-directory-p path)
           (not (s-ends-with? "/" path)))
      (funcall orig-fun server (concat path "/"))
    (funcall orig-fun server path)))